Iron manufacture.



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Para smut.

ROBERT BI CARNAHAN, JR., OF MIDDLETOWN, OHIO, ASSIGNOF. TO .THE INTERNA-TIONALMETAL PRODUCTS COMPANY, OF NEWARK, NEW JERSEY.

. men MANUFACTURE. 1

Specification of Letters Patent. Patented MIar. 21, 1911.

No Drawing. Application filed October 22, 1.908, Serial No. 459,056.Renewed February'B, 1911. Serial VT 0 all whom 'it may concern:

GAnN AHAN,

Be it known that I, ROBERT -13, J in, a citizen of the United States;residing ,at- Middletown, Butler'lcounty, Ohio, have invented certainnew and useful Improve;

in'ents in Iron Manufacture iof which the following is a specification.

the product-ion of an extraordinarily high grade of rolling mill andbloomery iron from comparatively low priced, material and by a methodcharacterized by special economy and regular certainty of result, willbe readily understood from the following description.

.' -My improved method of I manufacture Which-(l5 a process ofelimination from start to finishmay be carriedputas follows T .per cent.

charge.

First-{employ a high pow r ble of what might be termeil a particularly'fierce action, by preference a gas fired basic open-hearth furnace.

Second, charge the furnace" with pig iron or cast iron or molten iron orother carbonbearing 7 iron reduced" from ore, preferablyemploying ironwhose phosphorus and sulfur and silicon do not aggregate over 3.05

stitu'ted'iron or steel melting stock or mixed scrap 'to the extent ofper. cent. of the X Third, charge 111118 or limestone to reducesulfur'and phosphorus,the lime or limestone being preferably chargedprior tocharging the metal.

Fourth, melt the chargeand, by the em-| ployment of iron ore, refine -itas in the operation of the usual process for making mild steel, and, asin'that process, the iron ore may be all pharged into the molten bathorsome of it may be charged prior to or along with, the charging of themetal.

Fifth, refine to the stage usual at the point of tapping for high grade.mild steel, say .10 to .15 per" cent. carbon. I

Sixth, thereafter continuously raise the;

temperature as the carbon becomes reduced, continuing the operation tillanalysis by bath test shows that the sulfur, phosphorus, manganese,carbon and silicon do not in the aggregate exceed .14: per cent. Thetime required will be very much lessened if iron ore in excess iscontinuously added in thepres'ence of the increasing temperatures.

furnace capa-.

In practice 1 have, in cases, subin practice find theperiod of treatmentsumes from one to four hours more time than is employed in making highgrade The present invention, comprehending mild Steel. I

Seventln; let the tapping temperature reach about 2850 deg. F., and tapthe melted hot charge into a ladle or other receptacle.

Eighth, pour into ingot molds while still at high temperature, not below2775 deg. F.

Ninth,v degasify the molten metal, say with aluminum, in the same manneras in ordinary open-hearth practice with mild structive to furnaces,very muchmore so than anything met with in usual operations intheproduction of mild steel. -My experience up to-the present timeindicates that myprocess is about three times as destructiae to furnaceroofs as are the usual'processe s with similar furnaces.

I have above referred to a temperature of 2850 deg. F. for the bath andthis is correct as far as l have been able to ascertain from the mostreliable authorities and 8 5 literature. In practice, correcttemperaturemay be determined by stirring the bath with an iron rod oneand one-eighth inches in diameter for-one minute and a' quarter.

If about eighteen inches of the rod has been melted ofl and if thefluxed rod end has a glassy appearance the temperature is correct. Amore rapid or slower cutting away ofthe rod indicates thatthe bath istoo hot or too cold.

.The poured ingots represent a product extraordinary in the art, and theextraordinary characteristics of these ingots can be secured with adegree of regularity and certainty quite unattainable in any prev ouslyknown commercial inethod for theproduction of iron having theircharacter istics. "(The bodies of the ingots are free of slag. Theheads, of the ingots involved at the end of a pouring may show a trifleof slag but this is harmlessand drops off in the heating and working 'ofthe ingot and never enters the worked product. The

, extraordinary ularly producing a temperatures bodies of the ingotsWill be found free from s lag,'thus far detected by themicroscope in thehands of a professional metallographist which is, of course, the casealso with products worked from the ingots. Briefly, the product of myimproved method is iron of a purity exceeding that of thevery hi hestgrade of Swedish charcoal iron: an

and uncertainties incident to other methods of producing these highgrade irons, and my improved method is vastly more economi cal. Themethod is capable of yielding a product whose percentage of iron' isalmost identical with iron by hydrogen!" My improved method provides,for the first time in the history of-the art, so far as I am apprised ofit, for thetcommercial production in an'open hearth furnace of a productheretofore arrived at onlyin the laboratory. This may be judged of bythe fact that, Without considering the more refined capacities of mymethod, I am in every day practice in anopen" hearth furnaceregproductanalyzing as follows k S1l1con .Trace.

Manganeseu'un .010 Sulfur .019 Phosphorus a .003 Carbon a .027 Iron (bydifi'.) 99.941

Fourth will galvanize more satisfac-- torily than me.

Fifth :resi sts all corroding a cuts to an degree, being in t vastlysuperior to. anycommercial steel known to me, and equal to the veryhighest grades of Swedish charcoal iron. Sixth :forges and rolls withfacility at any comnlr ercial iron 'known to ear/tee the ,manufacture isnot subject to the variations 5 use in making *step's:--first, in

open hearth furnace w th iron: second, in

than steel, thereby cident tothe employment 0 high tempera,- tu'res. Thematerial is especially adapted for smooth sheets comparatively free fromscale, being, it isjbelieved, superior in this respect to any iron ormild steel known to the art.

ternal electrolysis.

Eighth: welds perfectly'with a flux,-but

charcoal or puddled iron without a-fl'ux.

Ninth :The product well lends itself to crucible steel, being superiorto ordinary iron and muc more economical than charcoal iron.

Tenth :the microscope has detected no slag in the body ished product.

Eleventh:the material combines in a most remarkable degree the mostvaluable qualities of commerciallmild steel and the most valuablequalities ofthe best commercial iron, with apparently none of the manyof the ingot or in the finundesirable qualities of either.-

The improved method of producing rolling-mill and bloomery ingots ofspecially high-purity iron consisting of the following charging ahighpowered employing therewith eliminating agents for carbon andmanganese and sulfur and phosphorus: third, in refining the charge instrength somewhat higher.

' p iorus, manganese, carbon is respect .niolten condition till carbonis about .10 per cent: fourth, in continuing the refinementatcontinually increasing he attill analysis by bath test shows that thesulfur, phosand silicon do .not in the aggregate exceed .14 percent..and with an ultimate bath temperature of at least 2850 deg. fifth, inpouring the metal being treated with a degasifying agent while in moltenstateafter tapping from the furnace, substantially as set forth.

. lVitnesses: 3

considerably lower than high ELMER RQSHIPLEY, M. S, .BELPEN.

'Seventh:substantially proof against in grade charcoal iron ai'id; verymuch: lower avoidln the scalingin without. a flux it welds lessperfectly than hot purified metal into ingot molds, the

wRO BERT 'BfCARNAHAN. JR.

